Neural Correlates of Value, Risk, and Risk Aversion Contributing to Decision Making under Risk

Decision making under risk is central to human behavior. Economic decision theory suggests that value, risk, and risk aversion influence choice behavior. Although previous studies identified neural correlates of decision parameters, the contribution of these correlates to actual choices is unknown. In two different experiments, participants chose between risky and safe options. We identified discrete blood oxygen level-dependent ( BOLD) correlates of value and risk in the ventral striatum and anterior cingulate, respectively. Notably, increasing inferior frontal gyrus activity to low risk and safe options correlated with higher risk aversion. Importantly, the combination of these BOLD responses effectively decoded the behavioral choice. Striatal value and cingulate risk responses increased the probability of a risky choice, whereas inferior frontal gyrus responses showed the inverse relationship. These findings suggest that the BOLD correlates of decision factors are appropriate for an ideal observer to detect behavioral choices. More generally, these biological data contribute to the validity of the theoretical decision parameters for actual decisions under risk.

A simulation and behavioral study of decision and risk in blackjack

The purpose of this master project was to explore decision making process applied to a blackjack game and make the links with facets of impulsivity. The first part of this study goes through the mathematical of this game and presented the optimal policy, computed with reinforcement learning algorithm. We also computed with a Monte Carlo simulation, for each possible hand and for each possible decision, the 3 values

{Q}_{t}

{H}_{t}

and

{h}_{t}

, value function, risk, one-step-ahead risk proposed by d'Acremont & Bossaerts, 2008. The second part of the study present the result of the behavioural study. Forty-seven undergraduate students perform 200 blackjack hands and completed a self-report questionnaire evaluating impulsivity and risk attitude. Our analysis reveals links with lack of perseverance and decision time. Furthermore percentage of optimal decision along the game reveals learning with novice player. The result of this study can be used as a basis for future research in neuroimaging on the risk, to try to answer if is possible to distinguish brain area associated with one-step ahead versus total risk

2009

Risk and Reward Preferences under Time Pressure

Anjali Devi Vanapilli Nursimulu

Financial decision making under time pressure, though ubiquitous, is poorly understood; classical and behavioral finance are silent about the time required for a decision to be made. In an experiment, calibrating allowable decision times to 1, 3, and 5 s, we find that classical moment-based preferences reflect time-invariant sensitivity to expected reward, purchase impulsiveness under extreme time pressure, and decreased aversion to variance and increased aversion to skewness with decision time. These timevarying sensitivities translate into increased probability distortions and decreased risk aversion for gains under prospect theory (PT). Strikingly, moment-based theory provides a better fit than PT.

Oxford Univ Press2014

A simulation and behavioral study of decision and risk in blackjack

{Q}_{t}

{H}_{t}

and

{h}_{t}

2009